24 Comments

Summary:

SIP stands for Session Initiation Protocol, and is to real-time communications what SMTP and e-mail are to message delivery, and is slated to become the next major revolution in the ways we humans communicate. Want to start playing? Start here.

SIP stands for Session Initiation Protocol, and is one of many ways to do Voice over the Internet Protocol, but its applications reach far beyond mere Voice. SIP is to real-time communications what e-mail is to message delivery, and is slated to power the next major revolution in ways we humans communicate … in real-time. on the Internet. For free. Or Cheap. Want to start playing? Start here.

Skype, while very powerful, remains a closed ecosystem that relies on everybody using the same software which complies to a closed protocol, within a system owned and operated by one entity who calls all the shots.

SIP is an open protocol, and Voice over IP through SIP relies on a set of other open protocols and standards, all of which work hand in hand to make real-time communications work. Anybody today can become an e-mail provider, write their own e-mail server software, or e-mail user program. The same holds true for real-time communications through SIP.

What are real-time communications? Voice. Text. Video Conferencing. iChat uses SIP for Voice and Video. While text still goes through AOL’s closed protocol.

It’s been around for a good 10 years, but hasn’t had a chance to make it onto the mainstream until a few technical challenges could be overcome, some of the more prominent ones being Network Address Translation and higher bandwidth. The STUN protocol which came out in 2003, provides developers with a standard way to circumvent Network Address Translation issues.

Our ducks are now in a row. We’re ready. How does it work?

Your “SIP program” registers its online presence with a “SIP Proxy”: “Hey, i’m on my home network right now, and I can be reached at this IP address”. When you arrive at work, your SIP program will now say “Yoohoo, i’ve moved, i’m now here!”.

If someone wants to call you, they’ll type your SIP address in their SIP program. The SIP provider will help this person’s SIP software get in touch with your computer‘s SIP software, partly thanks to some STUN magic thrown in the middle. A SIP address looks exactly like an e-mail address, and, with some providers such as EarthLink, can very-well be one and the same. In my case, you can send me an e-mail at hollandct@earthlink.net or plug hollandct@earthlink.net ( or sip:hollandct@earthlink.net ) in your SIP program to call me up. If i’m not online or available, you’ll hear my voicemail, which will then be delivered as a .wav attachment to my e-mail address … which Mail.app plays inline just fine!

You don’t even need a “SIP Provider” to do SIP. If you know your party’s IP address or host name, if their SIP software is properly configured, you can plug their IP address into your SIP program to give them a ring.

Having a SIP address just gives you a more universal way for people to get in touch with you.

What’s your SIP address?.

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  1. Nick Santilli Saturday, June 4, 2005

    Chris – this is awesome. Thanks for pointing this out to us. A new fun toy to play with. But lets get everyone using it so it’s more than a toy, and actually becomes useful!! For free, why the heck not??

    nice write up.

  2. Chris Holland Saturday, June 4, 2005

    eh you’re welcome, also one thing i prolly should mention in the main article is that sound quality will in most cases far surpass that of what you hear on the phone. It often depends on the SIP software you’re using and which codecs you’ve configured, but yeah it’ really nice. You’ll never want to go back to phones. I’m starting to tell people: don’t *ever* phone me again. SIP me! heh.

  3. The Apple Blog » Live WWDC Keynote Preparations Sunday, June 5, 2005

    [...] 217;re able to stream out some live audio, it will likely happen over SIP. You’ll want to read-up on SIP and SIP-powered audio conferencing [...]

  4. The Apple Blog » Flexibility, Interoperability in Communications Saturday, July 2, 2005

    [...] Holland A few posts back, I gave a layman’s overview of SIP, attempting to convey how important [...]

  5. Keebler/Blog » Blog Archive » Gizmo – A free phone for your computer Wednesday, July 6, 2005

    [...] ight into a closed protocol, a closed ecosystem solely controlled by one organization, the SIP protocol is open. Free open-source proxy/server implementation [...]

  6. Keebler/Blog » Blog Archive » Gizmo – A free phone for your computer Wednesday, July 6, 2005

    [...] ight into a closed protocol, a closed ecosystem solely controlled by one organization, the SIP protocol is open. Free open-source proxy/server implementation [...]

  7. Keebler/Blog » Blog Archive » Gizmo – A free phone for your computer Wednesday, July 6, 2005

    [...] ight into a closed protocol, a closed ecosystem solely controlled by one organization, the SIP protocol is open. Free open-source proxy/server implementation [...]

  8. Keebler/Blog » Blog Archive » Gizmo – A free phone for your computer Wednesday, July 6, 2005

    [...] ight into a closed protocol, a closed ecosystem solely controlled by one organization, the SIP protocol is open. Free open-source proxy/server implementation [...]

  9. The Apple Blog » New Gizmo Project Beta: Encrypted Calls! Wednesday, July 27, 2005

    [...] :username@provider.com) More background on SIP and the Gizmo Project: A layman’s introduction to SIP Interoperability Gizmo is coo [...]

  10. Have you heard of a company called Damaka (www.damaka.com).

    The are in the SIP P2P space and they have an application that lets you do instant message, chat, voice calls, audio conference up to four users, personalized voice mail, send SMS all from a laptop.

    Have you guys heard of this company and does anyone know about their product.

    I went to their site http://www.damaka.com because a friend of mine recommended it but I don’t know much about the company.

    Has anyone heard about Damaka or their product?

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